Hi ??
Does the decoder in the lok has switches to set the address?
If it does, try to set them all to "off" so the lok is in analog mode instead of Delta and then connect your transformer straight to the track bypassing the Delta controller.
The sound indeed sounds like a short circuit.
It is hard to see in the pics, but it looks to me the wiring from the transformer to the Delta controller is not right
Double check that one first

Regards
Jean-Pierre

Thanks yall for the great info! Awesome to know this resource is here!

I’ve checked a few of the engines, and I’m not finding any smaller switches to throw. I’ve checked 2916 (small steam engine) and an 2977 (ICE starter set). I wonder if these were made pre-switches, and are only analog?

I do wonder if there is something wrong with the powered rail. I don’t see any lights on when the trains are on the track (either connected through the Delta switch or when directly wired to the transformer). I’ve also triple checked to make sure that the wires are going from/to the correct spot (I don’t have corresponding colored wires to match but can confirm that O/B are wired correctly )

I’ve ordered another power rail and should arrive next week….wanting to rule that one out.

Thanks again for the help!

Let us try the simplest test.

Set all four dip switches to off. This should mean that the locomotive is in analog mode.

Attach the wire from the brown terminal to the left terminal on the rail section. Attach the wire from the red terminal to the right one on the rail section (middle rail).

Attach a second straight section to the contact track to give you a total of 180mm

Place the locomotive on the track. Provide a little power on the transformer.
Look for 1) Lights, 2) Motion and 3) Motor noise/hum

Hopefully everything now works. See below to correctly set the locomotives to work with the Delta control and connect it between the transformer and the track.
If it still does not work, let's go to the next step:

So, now that we have tested the basics, let us eliminate other potential issues...

Test the output of the transformer (not the Delta control) with a multimeter set to AC volts or connect a suitable light bulb 30VAC and see if it lights up. You can use the bulb (removed) from the steam engine if you don't have another one.

Since all of your locomotives are not working, we can assume it is not a problem with a single locomotive.
Let's test the track. Take a piece of masking tape and tape the ground (return wire) to one of the outer rails. Connect the red (live) to the right terminal of the track
Repeat the test above. If it works, there may be an issue with the ground terminal of your contact track.

Turn the locomotive upside down in some sort of box or cradle
To test the centre rail, tape the red (live) lead to the slider on the bottom of the locomotive
Touch the return wire to one of the wheels to see if the locomotive responds when power is provided

If it works, that basically confirms that the problem is with the track

Back to the locomotives:

There are many addresses that can be set using the 4 switch delta selector. The ones that are factory set are the ones that correspond to the addresses on the Delta controller, which are as follows:

1) Steam 1 - - - - (Digital 78)
2) Railcar 1 2 - - (Digital 72)
3) Diesel 1 - 3 - (Digital 60)
4) Electric 1 - - 4 (Digital 24)

There are other combinations that can be accessed using a Digital Control 6021

It seems that in the instructions of many models, positions 2 (Railcar) and 3 (Diesel) are inverted compared to the controls of the Delta controller. Mine Delta controller has them in the following order (L to R)
Stop - Steam - Diesel - Railcar - Electric - Stop

In order to use a locomotive with the Delta controller, you must select one of the 4 options and then you can control that locomotive only via the transformer.
With a 6021, you could control multiple digital or delta locomotives at the same time.

If there is a short in the video, the light on the transformer would dim. What happens when you plug the transformer in but don't connect it?
Then connect the Delta control but don't connect it to the track. What happens then?

More about the track. K track relies on a metal strip underneath the trackbed to conduct the centre rail power. At the end of each track piece, there are two metal plates that connect to the next track piece and transmit the power. If one of these pieces is bent, it may either cause a lack of contact or a short circuit. You should inspect all track sections as you assemble the layout. Based on your description of the sounds, you may have a short with a track.
The test for this is to start with just the contact track and add one section at a time, testing as you go.

One last thing about the models. Early 90s Maerklin was notorious for having oil that hardened and gummed up the gears/wheels. In such a case, you would hear some kind of humming from the model as the motor tries to turn and the lights would come on. If the lights don't go on, you can disregard this as that indicates a power rather than a mechanical issue.

One question about the 2977 and 2916. From what I could find, these sets came with M (Metal) track. Did your's come with K (plastic) track instead?

Regards

Mike C

Just wanted to shoot an update....it was the power track!

I ordered a new one off Amazon. Arrived today, I immediately ran upstairs to see if it works, and it did! Train lights powered on, and the one I tested moved.

I immediately stopped it as I also have some oil on order as well. Will be sure to thoroughly clean the trains before go hog wild.

woot woot!